Answer:
Step-by-step explanation:
Let's solve this by making an equation.
$9 for the helmet, and $5.25 per hour.
h will stand for hours, C will stand for Amanda's cost.
Now, substitute in what we learned from the problem.
This is an equation you can use to solve for the hours.
3(x - 1) = 2x + 9
3x - 3 = 2x + 9
3x (-2x) -3 (+3) = 2x (-2x) + 9 (+9)
(3x -2x) = (9 + 9)
(x) = (18)
x = 18
x = 18 is your answer
hope this helps
Answer:
45%
Step-by-step explanation:
i believe it to be true
Step 1: Writing Null and Alternate HypothesisFirst we need to write the Null and Alternate Hypothesis for this problem.
Researcher claims that mileage will be increased on addition of Fuel additive. So the null and alternate hypothesis will be:
: μ ≤ 25.1 (Null Hypothesis)
: μ > 25.1 (Alternate Hypothesis)This is a Right Tailed Test. Since population standard deviation is not know, we will use t-test to check the researchers claim.
Step 2: Finding Test StatisticSample Mean = x = 26.8
Standard Deviation = s = 3.9
Sample Size = n = 35
Degrees of Freedom = df = n - 1 = 34
Test statistic(t) is given by:
Step 3: Finding p valueUsing t table or calculators find the p value for t=2.579 with 34 degrees of freedom for one tailed test.
P value comes out to be:
p = 0.0072
Step 4: ConclusionSince the p value is lesser than the significance level of 0.05, we reject the Null Hypothesis.
We have enough evidence to support the researcher's claim that the new additive increases the miles per gallon of the cars.
